Smoking articles

ABSTRACT

A smoking article or attachment is provided with means by which a puff is divided automatically into a first portion and at least one later portion and the smoke portions produced are differentially and/or separately filtered. The puff-dividing means may be a valve device subject to the suction produced by the puff and arranged to control the opening of a smoke passage additional to a constantly open smoke passage. The constantly open passage opens into a high-density filter region and the additional passage into a lower-density filter region.

United States Patent [72} Inventor Fred Haslam Southampton, England [21]Appl. No. 859,388

[22] Filed Sept. 19, 1969 [45] Patented Dec. 28, 1971 [73] AssigneeBrown and Willamson Tobacco Corporation Louisville, Ky.

[32] Priority Nov. 27, 1968 [3 3] Great Britain [54] SMOKING ARTICLES 3Claims, 3 Drawing Figs.

52 us. Cl 131/261 B, 131/103, 131/10], 131/215 A, 131/215 B [51] Int. Cl..A24d 01/04, A24f07/04 [50] Field of Search 131/105,

[56] References Cited UNITED STATES PATENTS 1,543,043 6/1925 Allen131/215 B UX 2,850,021 9/1958 l3l/215B 3,463,166 8/1969 Bennett et a]131/223 X FORElGN PATENTS 1,094,642 12/1967 Great Britain 13 l/l0.7

Primary ExaminerSamuel Koren Assistant Examiner-J. F. PitrelliAttorney-Kane, Dalsimer, Kane, Sullivan and Smith ABSTRACT: A smokingarticle or attachment is provided with means by which a puffis dividedautomatically into a first portion and at least one later portion andthe smoke portions produced are differentially and/or separatelyfiltered. The puff-dividing means may be a valve device subject to thesuction produced by the puff and arranged to control the opening of asmoke passage additional to a constantly open smoke passage. Theconstantly open passage opens into a high-density filter region and theadditional passage into a lower-density filter region.

PATENTEDnaczman 3,530,210

sum 2 OF 2 v FIG. 3

1 SMOKING ARTICLES This invention concerns improvements relating tosmoking articles, especially but not exclusively cigarettes.

It is known from experimental work using automatic smoking engines thatthe composition of the tobacco smoke from smoking articles can bealtered by changes in puff volume, puff frequency, and the velocity ofthe airstream during puffing. Consideration of the results obtained fromsuch experiments suggests that the concentration of the more involatile,less desirable, .compounds occurring in tobacco smoke is higher in thefirst portion of the puff than in the later part.

According to the invention, a smoking article is provided with means bywhich a puff is divided automatically into a first portion and at leastone later portion and the smoke portions produced are differentiallyfiltered.

Also according to the invention, a device adapted for at tachmentto aconventional smoking article comprises means for dividing a puff ofsmoke automatically into a first portion and at least one later portionand filter means arranged to filter the smoke portions produceddifferentially.

Suitably, the first smoke portion of the puff comprises the portiondelivered during the first quarter to the first half of the duration ofthe puff.

Two embodiments of the invention, as applied to cigarettes, will now bemore fully described by way of example and with reference to theaccompanying drawings, in which:

FIGS. 1 and 2 are diagrammatic longitudinal sections through the saidembodiments, and

FIG 3 is a diagram in which pressure drop is plotted against time.

Referring to FIG. 1, the complete smoking article shown comprises atobacco-containing section 1, a valve section 2 and a filter section 3.The section 1 may be of the nature of a conventional cigarette withtobacco 4 contained in a paper wrapping 5. The section 2 comprises ashort cylinder 6 of cigarette diameter made of metal or a plasticsmaterial and attached in abutting relation to the section 1 by anadhesive band 7. A substantially complete narrow annular passage 8 orring of narrow passages through the cylinder 6 near its periphery allowsfree flow of smoke during puffing. A larger axial passage 9 through thecylinder 6 is connected by axially spaced radial ports 10, 11 to afurther substantially annular passage 12 extending for a substantialdistance, but not completely through, the length of the cylinder. Theaxial passage 9 is normally obturated at the end adjacent to the section1 by a resiliently loaded valve body. in the example, the valve bodycomprises a ball or spherical plug 13 retained in the obturatingposition illustrated, i.e. upstream of the radial ports 10, by a lighthelical compression spring 14 disposed in the axial passage 9. Thefilter section 3 secured in abutting relation to the section 2 by anadhesive band 15 comprises conventional fibrous or sheettobacco-smoke-filtering material in a wrapper 16. At least theperipheral region 17 of the filter adjacent to the exit orifice of theannular passage 8 is of higher density, or has higher smoke-retentionproperties, than the inner or axial region 18, from which it isseparated by a cylindrical paper sleeve 17'. A higher pressure drop isproduced in the region 17 than in the region 18. 1

In use, when initial suction is applied to the smoking article throughthe section 3, smoke is drawn only through the narrow passage 8, thevalve body 13 remaining in the obturating position. This initial portionof the puff passing through the passage 8 is filtered by thehigh-density filter region 17. As suction continues to be applied, thevalve body 13 is retracted just pass the radial ports 10 and, whilestill closing the axial passage 9 for the middle portion of its length,permits smoke from the section 1 to pass into the annular passage 12 andso, via the ports ll, to the lower density filter region 18. The smokepath through the passage 8 and filter region 17 is thus bypassed to anextent which can bepredetermined by design.

With such a device, the smoke produced during the earlier part of thepuff is more strongly filtered, at 17, than thesmoke of the later partof the puff, at 18, whereby more efficient filtration and a moredesirable composition of the smoke entering the smokers mouth can beensured.

The smoking article of HG 2 differs from that of FIG. 1 in that thelower density inner filter region 18a is enclosed to the rear, as wellas circumferentially, by the higher density filter material of theregion 17a. A similar differential filtration effect is obtained.

FIG. 3 in which the pressure drop PD in smoking article in accordancewith the invention is plotted against time T, illustrates, in generalprofile only, an example of a two-portion puff comprising a brief,initial, high peak 19 followed by a maintained lower value 20 of thepressure drop. The diagram is not dimensional, but the whole puff may,for the sake of example, be assumed to have a duration of about 2seconds.

lclaim:

l. A filter device adapted to be inserted between the tobacco of asmoking article and the mouth of a smoker for automatically dividing apuff into a first portion and at least one later portion anddifferentially and separately filtering each portion comprising a filtersection having first and second filter regions and a valve sectionpositioned between the said filter section and the tobacco, said valvesection including a constantly open smoke passage to the first filterregion and an additional passage to the second filter region, saidadditional passage embodying a spring-loaded valve subject to thesuction produced by the puff and positioned to control the opening ofthe additional passage.

2. The filter device of claim I in which the first filter region is ofhigh density and the second filter region is of lower density.

3. The filter device of claim 1 in which the additional passageembodying the valve is provided with axially spaced radial ports leadingto a substantially annular passage bypassing the valve.

2. The filter device of claim 1 in which the first filter region is ofhigh density and the second filter region is of lower density.
 3. Thefilter device of claim 1 in which the additional passage embodying thevalve is provided with axially spaced radial ports leading to asubstantially annular passage bypassing the valve.